Advances in medical care have allowed a greater number of neonates to survive. The result has been an increase in the number of infants at risk for later intellectual retardation. Happily, some 80 to 90% of high-risk infants are intellectually normal later in life. The commercial development of a valid screening device for differentiating infants who will later be intellectually normal from those who will later be retarded has two advantages. The first is that parents of the majority of infants screened could be relieved of their anxiety and could be encouraged to treat their infants as intellectually normal. The second is that identification of mental retardation during infancy may allow a fuller understanding of the causes of such deficit. The main aim of the proposed project is to make a screening device available to clinicians so that infants who will later be intellectually normal or mentally retarded may be identified during the first year of life. The Fagan Test of Infant Intelligence (copyright 1981, J. F. Fagan III) is a valid screening device for the early identification of later mental retardation. Currently, the Fagan Test exists solely as a research instrument. The specific goal of this Phase I project is to develop and to field-test a prototype of the Fagan Test of Infant Intelligence which may be used by clinicians. The distribution of the clinical prototype to neonatologists for an extensive clinical trial will be the aim of a Phase II project. Ultimately, the prevention or remediation of mental retardation is more likely when early identification of the victims and the causes of retardation can be made. The commercial development of a valid screening device for the early detection of intellectual deficit promises to aid in diagnosing, understanding, and, potentially, in preventing or alleviating mental retardation.